CDH1 and neoplasm: There is considerable uncertainty regarding this entity of mixed tumors.39 Prior studies indicate that this terminology may be variably used to describe tumors with intermixing of E-cadherin-negative and E-cadherin-positive cells, a collision tumor of a separate ILC and IDC, or tumors with a morphologically lobular growth pattern yet E-cadherin positivity.40 Additionally, the World Health Organization classification criteria for mixed invasive cancers have changed over time.